IMO with charging your sigil pick a method that affirms the desire/intent of the sigil. For example, if your desire is that of a hex or destruction then charging it with blood might be an option. If not but prosperity create a sigil with those signs and words, blood isn’t needed, you can also render an offering, wine, or candy, perhaps a favored crystal.
Getting into a trance state where the sigil can leave a lasting impact on the subconscious is key to successfully charging a sigil. By chanting the mantras of your goal, a trance state can be achieved.
Although this method is slower and time consuming, your trance state lasts longer, enabling you to charge sigils effectively. Your focus is the key repeating the goal in your mind and saying it out loud will help achieve your goal.